The present invention relates generally to optical fiber sensors, and more particularly to a tapered optical fiber sensor for measuring a physical effect or phenomenon.
Optical fiber sensors are well-known in the art. Highly sensitive ones are usually configured as optical interferometers requiring a single-frequency light source as well as one or more optical fiber couplers. Although highly sensitive, these devices are relatively complex. Less complex but less sensitive devices are usually made from multi-mode fibers and LEDs in which the amplitude of the light through the fiber is altered by the perturbation being sensed. No current design of optical fiber sensor offers high sensitivity without the complexity.
Single-mode tapered fibers have been studied and used as fused, tapered couplers and polarization controllers. Light loss as a function of taper length in tapered fibers has also been studied. The sensitivity of tapered fibers to bending has not, however, been realized or exploited as a sensor.